The master comprises a polyester resin as a binder resin and a carbon black as a colorant having a primary particle size of 10 nm to 100 nm, is blended with 30 to 60 parts by weight of the carbon black, has a lightness L* of 20 or more; and the reflectance A at 400 nm thereof and the reflectance B at 700 nm thereof fall within the range satisfying the relation given by the following formula 1:0. A ball assembly including a ball portion forms a spheroidal joint with the cavity which enables conical movement of the ball assembly. A capacitor dielectric overlies the bottom electrode.